This invention relates to test systems and more specifically to a system using simulated messages at specific system interfaces.
Software systems are becoming increasingly complex and as the complexity grows so does the complexity of the test procedures used to verify the validity of system operation. Such test procedures are used at various stages of system development. For example, many software systems are divided into layers or subsystems with each section designed by a different team of computer scientists to perform certain specific functions. Often it is desired to test and verify the integrity of a section design even before the other subsystems are complete.
In communication systems, in addition to the internal interfaces between software sections, there is a complex interface between the system and communication terminals connected to the system. Prior to connecting actual users to the system it is necessary to test overall system performance under a wide variety of conditions and under various simulated loading. Problems exist when it is desired to perform these tests prior to the availability of either the interface circuits or the actual terminals.
Other problems, such as simulating the actual communication connection or an actual loading situation, are presented even when the entire system is complete because it is impractical to actually place the calls through the system. These problems deal, primarily, with finding faults in the software, that might only provide an instantaneous fault condition. Problems also occur when testing during the development state of the system, since it is not always clear that the system will behave as expected and thus the internal controls of the system cannot be relied upon to provide error messages or error control.